1. Field of the Invention
The present invention generally relates to the treatment of arterial disease including, for example, an abdominal aortic aneurism or occlusive disease of an artery. More particularly, the present invention relates to an improved method for treating arterial disease using a novel intraluminal vascular stent formed of a meshwork of inflatable conduits. This construction provides for readily deploying the stent and for repositioning it should the stent not be initially deployed in the most optimum position in the vasculature.
2. Prior Art
The prior art describes the treatment of arterial disease by various surgical techniques, some involving the use of stents and grafts. For example, it is well known to interpose a stent within a diseased portion of the human vasculature to prop open and support the vasculature and provide unhindered fluid flow there through. Conventional stents are made of stainless steel wire, Nitinol wire and the like constructed in a meshwork form. Such stents are balloon or self-expandable inside an arterial lumen to provide for supporting and strengthening the walls of a stenotic or occluded artery. Similarly, it is well known in the prior art to use a graft in conjunction with a stent to repair damaged portions of the aorta or other arteries. Grafts, comprised of hollow tubes of prosthetic material such as Dacron, are normally inserted within the walls of a damaged artery and can be deployed into position through the use of a stented balloon catheter, thereby ensuring blood flow and reducing the risk of an aneurysm rupturing.
One of the problems with current stent designs is that it is difficult to control the supporting force which they exert against the vasculature side wall. Although the inflation pressure of the balloon catheter can be controlled, once the balloon is deflated and removed leaving the deployed stent in place, the force of the stent supporting the vasculature wall can change over time. Eventually, it is possible that a conventional wire mesh stent could become fatigued and bend and fracture to the extent that the supporting force it exerts is less than desirable to maintain open and unhindered flow through the vasculature. Conventional practice is to re-enter the treatment zone with a balloon catheter which is moved inside the relaxed stent and inflated to re-position the stent against the vasculature side wall. If the stent has relaxed to the point that it no longer sufficiently supports the vasculature wall, it must be removed and replaced.
U.S. Pat. Nos. 4,183,102 to Guiset and 5,370,691 to Samson describe inflatable devices for supporting the vasculature. However these devices do not provide a meshwork of intersecting conduits as in the present invention. Guiset disclosed a plurality of hollow toroidal sleeves while Samson relates to a helically wound polymeric tubing. These devices do not provide for lateral flow at the junction of two arteries, for example.
The present invention solves the drawbacks of the prior art by providing a novel inflatable intraluminal vascular stent or stented graft and method for treating vasculature diseases. The inflatable characteristic of the present stent means that the supporting force exerted by the stent will not change. Also, the present inflatable stent is selectively deflatable for repositioning should it later be determined that the stent is not positioned in the most desirable location within the vasculature.